Sanitary napkins have customarily included a central absorbent element having a body facing side, a garment facing side, longitudinally extending sides and transverse ends, In the past, these products sometimes failed to provide proper protection because the edges of the crotch of the panty, to which these products are adhered, tended to enfold onto the body facing side of the napkin. This condition can cause the panty to be stained with body fluid, either emanating from the napkin or exuding from the body of the wearer.
In order to overcome this deficiency, several of the more recent napkin designs have included flaps extending along the longitudinal sides of the absorbent element. Mattingly, U.S. Pat. No. 4,608,047, for example, is directed to such a sanitary napkin having flaps extending from a central absorbent. This product is adhesively attached to an inner crotch portion of a user's undergarment and its side flaps are then folded onto an outer surface of the crotch portion to protect the garment. McNair, U.S. Pat. No. 4,285,343, is also directed to a napkin having flaps for folding over the outer surface of the wearer's garment. Both of these patents provide for embodiments that include absorbent pads in their flaps, thereby inviting the transmission of body fluid from the central absorbent element While sanitary napkins with wings or flaps have been designed to provide superior protection from fluid staining from the sides of the napkin, staining can often occur due to the transmission of body fluid from the transverse ends of these napkins Accordingly, there is a need for limiting or delaying the transmission of fluid to the ends of these napkin designs so as to minimize "product failure".
In prior art sanitary napkins not having flaps extending laterally from their absorbent element, the techniques of indenting or compressing a portion of the central absorbent for assorted reasons has been suggested.
Matthews et al. U.S. Pat. No. 4,397,644, is directed to a sanitary napkin having an additional comfort layer disposed between the principle absorbent and the fluid permeable cover. This comfort component is integrated with the cover to provide intimate contact and densification to localized regions of the product. These densified regions create fluid transfer routes, whereby viscous body fluids can be directed into the principle absorbent. The densification of the additional absorbent component of Matthews, however, is designed for transferring, rather than delaying the transmission, of body fluid.
Mogor, U.S. Pat. No. 3,575,174, is directed to a sanitary napkin which is maintained in a shaped configuration by deep embossed channels impressed through the cover and into the core of the napkin to compression bond the two components together The deep embossed channels are positioned near the lateral end edges on the top surface of the napkin and at the rearward end on the bottom surface of the napkin. The embossed channels are designed to shape the sanitary napkin for fit against the body of the wearer. This design is not intended to create delayed absorbency, nor is there a teaching for absorbent wings that provide protection by wrapping around the outer portion of the panty.
Joa, U.S. Pat. No. 2,721,554 is directed to a sanitary napkin having a pair of absorbent pads with a liquid-permeable tissue interposed between the pads for regulating the flow of liquid between the two absorbent elements. The patent teaches the use of a compression molding of the two pad elements near the transverse ends of the napkin for adhesion of the pads to each other through pressure knitting of their fibers at these localized zones. The invention further directs that one of the pads should be shorter than the other so that the thickness of the pad at its ends may be reduced without undue compression of the pulp. This patent, therefore, is not directed to delayed or compartmentalized absorbency, but rather, employs compressed areas of the pulp as a means for joining two pulp portions together
Hirsch, U.S. Pat. No. 2,154,332 is directed to a sanitary utility pad having a petal construction with a pocket or depression for initially catching any fluid to be absorbed so that it will not run off the pad. The pocket of this invention appears to be a cut out of the central absorbent, rather than being a compressed portion of the pulp. The object of this device is to provide sufficient time for the filler or inner portion of the absorbent to absorb the body fluid before it runs off the fluid pervious surface. There is no teaching in this patent, however, for delayed absorption through the napkin by the extremities of the central absorbent.
Whitehead, U.S. Design Pat. Nos. 247,369, 247,370, 247,371, 247,372 are directed to ornamental designs for a contoured sanitary napkin, illustrating patterns embossed on the body-facing side of the napkin. These designs, however, do not appear to be directed to delayed absorbency and are primarily directed to aesthetic appearance.
German Patent 959,814, Mar. 14, 1957, is directed to a diaper configuration with a notched central absorbent area having a water-tight cover on its body facing side and perforations in the bottom of the notched areas for transmitting fluid to the product's absorbent tissue.
Canadian Pat. No. 884,608 (issued Nov. 2, 1971 to Yvon G. Levesque) describes a product and method for inhibiting liquid leakage at the edges of an absorbent product which contains a continuous hydrophobic gas and vapor permeable open-pore zone about the edge margin of the product.
While at least one of the above-mentioned patents, Hirsch, suggests preventing leakage of body fluid from the transverse ends of a sanitary napkin, none of these references is directed to sanitary napkins having panty-protecting flaps. Accordingly, if one were to compartmentalize the transverse ends of a central absorbent of a typical prior art napkin, body fluid would merely be directed to the longitudinal sides of the napkin which may have relatively little absorbing capacity, or none at all.
Accordingly, there is a need for a sanitary napkin, having absorbent flap portions, that provides a means for preventing the transmission of body fluid from its transverse ends. There is also a need for a compartmentalized sanitary napkin having reserve absorbent capacity on its transverse ends and longitudinal sides